V2X communication device and geo-networking transmission method

ABSTRACT

A geo-networking transmission method of a V2X communication device includes using hybrid communication including direct communication and cellular communication. The method includes receiving a message from at least one neighboring vehicle and transmitting a geo-networking packet to at least one neighboring vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage filing under 35 U.S.C. 371 ofInternational Application No. PCT/KR2018/008309, filed on Jul. 23, 2018,the contents of which is hereby incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The disclosure relates to a V2X communication device and ageo-networking transmission method, and in particular, to ageo-networking transmission method using hybrid communication includingdirect communication and cellular communication.

BACKGROUND ART

In recent years, vehicles have become a result of complex industrialtechnology, which is a fusion of electric, electronic, and communicationtechnologies, centering on mechanical engineering and the vehicle isalso called a smart car in such an aspect. Smart cars have beenproviding various customized mobile services as well as traditionalvehicle technology, such as traffic safety/complicatedness by connectingdrivers, vehicles, and transportation infrastructures. The connectivitymay be implemented using vehicle to everything (V2X) communicationtechnology.

DETAILED DESCRIPTION OF THE DISCLOSURE Technical Problem

Various services may be provided via V2X communication. A plurality offrequency bands are used to provide various services. Even in such anenvironment, high-reliable transfer and delivery of a safety service isa significant issue in light of the nature of vehicular communication.

In V2X communication, in order to transmit data out of the transmissionrange, a geo-networking transmission method using hopping may be used.In geo-networking transmission, a packet forwarding algorithm may beused for data hopping and destination delivery. In particular, in a V2Xcommunication environment in which the communication environmentdynamically changes, the efficiency and reliability of the packetforwarding algorithm need be considered.

Technical Solution

To address the foregoing issues, according to an embodiment of thedisclosure, a method of geo-networking transmission using hybridcommunication including direct communication and cellular communicationcomprises receiving a message from at least one neighboring vehicle andtransmitting a geo-networking packet to the at least one neighboringvehicle. The transmission of the geo-networking packet may be performedbased on at least one forwarding algorithm of a greedy-based forwardingalgorithm, a sender-managed forwarding algorithm, or a contention-basedforwarding algorithm.

In the geo-networking transmission method according to an embodiment ofthe disclosure, the received message may include hybrid capabilityinformation for the neighboring vehicle. The hybrid capabilityinformation may indicate whether the neighboring vehicle is capable ofthe hybrid communication.

In the geo-networking transmission method according to an embodiment ofthe disclosure, the received message may include cellular in rangeinformation. The cellular in range information may indicate whether theneighboring vehicle is within coverage of a cellular base station.

In the geo-networking transmission method according to an embodiment ofthe disclosure, the geo-networking packet may include forwardingalgorithm type information. The forwarding algorithm type informationmay identify a type of forwarding algorithm through which thegeo-networking packet is transmitted.

In the geo-networking transmission method according to an embodiment ofthe disclosure, the greedy-based forwarding algorithm may include atleast one type of an enhanced greedy forwarding 1 (EFG1) algorithm or anenhanced greedy forwarding 2 (EFG2) algorithm, the sender managedforwarding algorithm may include at least one type of a sender managedforwarding 1 (SMF1) algorithm or a sender managed forwarding 1 (SMF2)algorithm, and the contention-based forwarding algorithm may include anenhanced contention-based Forward 1 (ECBF1) algorithm, an enhancedcontention-based forward 2 (ECBF2) algorithm, a combined sender-basedand contention-based forwarding (CSCF) algorithm, an enhance combinedsender-based and contention-based forwarding 1 (ECSCF1) algorithm, or anenhance combined sender-based and contention-based forwarding 2 (ECSCF2)algorithm.

In the geo-networking transmission method according to an embodiment ofthe disclosure, when the transmission of the geo-networking packet isperformed based on the contention-based forwarding algorithm, abuffering time of a timer for packet forwarding may be determined basedon at least one of a hybrid communication capability of a receiverreceiving the geo-networking packet or whether the receiver is withinthe cellular coverage.

To address the foregoing issues, according to an embodiment of thedisclosure, a V2X communication device performing hybrid communicationincluding direct communication and cellular communication comprises amemory storing data, a communication unit transmitting and receiving awireless signal including a geo-networking packet and a processorcontrolling the memory and the communication unit. The processorreceives a message from at least one neighboring vehicle and transmits ageo-networking packet to the at least one neighboring vehicle. Thetransmission of the geo-networking packet may be performed based on atleast one forwarding algorithm of a greedy-based forwarding algorithm, asender-managed forwarding algorithm, or a contention-based forwardingalgorithm.

Advantageous Effects

The disclosure may reduce the number of hops required and solve theproblems with geo-networking by using cellular technology. Since thenumber of hops required is reduced, the transmission reliability, theoverall delivery delay and network traffic are enhanced. Reducing thenumber of hops may alleviate the problems with geo-networking protocols.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiments of the disclosuretogether with the detailed description serving to describe the principleof the disclosure.

FIG. 1 illustrates an intelligent transport system (ITS) according to anembodiment of the disclosure.

FIG. 2 illustrates a V2X transmission/reception system according to anembodiment of the disclosure.

FIG. 3 illustrates a configuration of a V2X system according to anembodiment of the disclosure.

FIG. 4 illustrates a packet structure of a network/transport layeraccording to an embodiment of the disclosure.

FIG. 5 illustrates a configuration of a V2X system according to anotherembodiment of the disclosure.

FIG. 6 illustrates a WSMP packet configuration according to anembodiment of the disclosure.

FIG. 7 illustrates a conceptual internal architecture of an MAC sublayerperforming a multi-channel operation (MCO) according to an embodiment ofthe disclosure.

FIGS. 8(a) to 8(c) illustrate a geo-networking transmission methodaccording to an embodiment of the disclosure.

FIGS. 9(a) to 9(c) illustrate a geo-networking transmission method usinghybrid communication according to an embodiment of the disclosure.

FIG. 10 illustrates a use scenario for geo-networking using hybridcommunication according to an embodiment of the disclosure.

FIGS. 11(a), and 11(b) illustrate a use scenario for geo-networkingusing hybrid communication according to an embodiment of the disclosure.

FIG. 12 illustrates a usage scenario for geo-networking using hybridcommunication according to an embodiment of the disclosure.

FIG. 13 illustrates a basic forwarding algorithm using hybridcommunication when a destination exists in the direct communicationrange of a sender.

FIG. 14 illustrates a basic forwarding algorithm using hybridcommunication when a sender exists within the coverage of a cellularbase station.

FIG. 15 illustrates a basic forwarding algorithm using hybridcommunication when a destination exists within the coverage of acellular base station.

FIG. 16 illustrates a use scenario of a first embodiment (EGF1) of anenhanced greedy forwarding algorithm according to an embodiment of thedisclosure.

FIGS. 17(a), and 17(b) illustrate a configuration of a CAM according toan embodiment of the disclosure.

FIGS. 18(a), and 18(b) illustrate a configuration of a BSM according toan embodiment of the disclosure.

FIG. 19 illustrates a use scenario of a second embodiment (EGF2) of anenhanced greedy forwarding algorithm according to another embodiment ofthe disclosure.

FIG. 20 illustrates a configuration of a CAM according to an embodimentof the disclosure. FIG. 20 illustrates an embodiment in which cellularrange information is included in an HF container. FIG. 20 illustrates anembodiment, in which the cellular range field may be included in acontainer/field different from that of FIG. 20 .

FIG. 21 illustrates a configuration of a BSM according to an embodimentof the disclosure.

FIG. 22 is a flowchart illustrating a forwarding algorithm of EGF1and/or EFG2 according to an embodiment of the disclosure.

FIG. 23 illustrates a use scenario of a first embodiment (SMF1) of asender managed forwarding algorithm according to an embodiment of thedisclosure.

FIG. 24 illustrates a use scenario of a second embodiment (SMF2) of asender managed forwarding algorithm according to an embodiment of thedisclosure.

FIG. 25 illustrates a use scenario of a first embodiment (EFBF1) of anenhanced contention-based forwarding algorithm for hybrid communication.

FIG. 26 is a view illustrating an execution operation of an ECVF1algorithm according to the embodiment of FIG. 25 .

FIG. 27 illustrates a use scenario of a second embodiment (EFBF2) of anenhanced contention-based forwarding algorithm for hybrid communication.

FIG. 28 is a view illustrating an execution operation of an ECVF2algorithm according to the embodiment of FIG. 26 .

FIG. 29 illustrates a use scenario of a Combined Sender-based andContention-based Forwarding (CSCF) algorithm according to an embodimentof the disclosure.

FIG. 30 is a view illustrating an execution operation of a CSCFalgorithm according to the embodiment of FIG. 29 .

FIG. 31 illustrates a first embodiment of an Enhance CombinedSender-based and Contention-based Forwarding (ECSCF) algorithm usinghybrid communication according to an embodiment of the disclosure.

FIG. 32 illustrates a second embodiment of an Enhance CombinedSender-based and Contention-based Forwarding (ECSCF) algorithm usinghybrid communication according to an embodiment of the disclosure.

FIG. 33 illustrates a configuration of a common header of ageo-networking packet according to an embodiment of the disclosure.

FIG. 34 illustrates a configuration of a common header of ageo-networking packet according to an embodiment of the disclosure.

FIG. 35 illustrates propagation of forwarding type information accordingto an embodiment of the disclosure.

FIG. 36 illustrates an information flow when a cellular network is notavailable according to an embodiment of the disclosure.

FIG. 37 illustrates an information flow when a cellular network isavailable according to an embodiment of the disclosure.

FIG. 38 illustrates a V2X communication device according to anembodiment of the disclosure.

FIG. 39 illustrates a geo-networking transmission method using hybridcommunication including direct communication and cellular communicationaccording to an embodiment of the disclosure.

MODE FOR CARRYING OUT THE DISCLOSURE

Preferred embodiments of the disclosure are described in detail andexamples thereof are illustrated in the accompanying drawings. Thefollowing detailed description with reference to the accompanyingdrawings is intended to illustrate the preferred embodiments of thedisclosure rather than merely illustrating embodiments that may beimplemented according to embodiments of the disclosure. The followingdetailed description includes details in order to provide a thoroughunderstanding of the disclosure, but the disclosure does not require allof these details. In the disclosure, respective embodiments describedbelow need not be particularly used separately. Multiple embodiments orall embodiments may be together used and specific embodiments may beused as a combination.

Most of the terms used in the disclosure are selected from the generalones that are widely used in the field, but some terms are arbitrarilyselected by the applicant and the meaning thereof will be described indetail in the following description, as necessary. Accordingly, thedisclosure should be understood based on the intended meaning of theterm rather than the mere name or meaning of the term.

The disclosure relates to a V2X communication apparatus and the V2Xcommunication apparatus is included in an Intelligent Transport System(ITS) to perform all or some functions of the ITS. The V2X communicationapparatus may communicate with vehicles and vehicles, vehicles andinfrastructure, vehicles and bicycles, and mobile devices. The V2Xcommunication apparatus may be abbreviated as a V2X apparatus. As anembodiment, the V2X apparatus may correspond to an on board unit (OBU)of the vehicle or may be included in the OBU. The OBU may also bereferred to as on a board equipment (OBE). The V2X apparatus maycorrespond to a roadside unit (RSU) of the infrastructure or may beincluded in the RSU. The RSU may also be referred to as a roadsideequipment (RSE). Alternatively, the V2X communication apparatus maycorrespond to an ITS station or may be included in the ITS station. Allof a predetermined OBU, a predetermined RSU, and a predetermined mobileequipment that perform V2X communication may also be referred to as theITS station or the V2X communication apparatus.

FIG. 1 illustrates an intelligent transport system (ITS) according to anembodiment of the disclosure.

The intelligent transport system means a system that provides anefficient and safe transport service by applying information andcommunication technology such as an electronic control and communicationdevice to transportation means such as automobiles, buses, trains, orthe like and transportation facilities including traffic lights, anelectronic display board, and the like. In order to support the ITS,vehicle to everything (V2X) technology may be used. V2X communicationtechnology represents communication technology between vehicles orbetween the vehicle and a peripheral device.

A vehicle that supports V2X communication is equipped with the OBU andthe OBU includes a dedicated short-range communication (DSRC)communication modem. An infrastructure including a V2X module installedaround a road, such as the traffic light, may be referred to as an RSU.Vulnerable road users (VRUs) are transportation weakness andpedestrians, bicycles, wheelchairs, etc. may correspond to the VRUs. TheVRU may perform V2X communication.

Vehicle to vehicle (V2V) refers to inter-vehicle communication orcommunication technology including a V2X communication apparatus.Vehicle to infra-structure (V2I) refers to communication orcommunication technology between the vehicle and an infra-structureincluding the V2X communication apparatus. Besides, communicationbetween the vehicle and the transportation weakness may refer to V20 andcommunication between the infra-structure and the transportationweakness may refer to I2O.

FIG. 2 illustrates a V2X transmission/reception system according to anembodiment of the disclosure.

A V2X transmission/reception system includes a V2X transmitter 2100 anda V2X receiver 2200 and the transmitter and the receiver aredistinguished from each other according to roles of transmitting andreceiving data and are not different from each other in a configurationof a device. The V2X transmitter 2100 and the V2X receiver 2200 are boththe V2X communication apparatuses.

The V2X transmitter 2100 includes a Global Navigation Satellite System(GNSS) receiver 2110, a DSRC radio 2120, a DSRC device processor 2130,an application Electronic Control Unit (ECU) 2140, a sensor 2150, and ahuman interface 2160.

The DSRC radio 2120 may perform communications based on the IEEE 802.11standard based on a Wireless Local Area Network (WLAN) and/or theWireless Access in Vehicular Environments (WAVE) standard of the Societyof Automotive Engineers (SAE). The DSRC radio 2120 may performoperations of a physical layer and an MAC layer.

The DSRC device processor 2130 may decode a message received by the DSRCradio 2120 or decode a message to be transmitted. The GNSS receiver 2110may process GNSS and acquire positional information and temporalinformation. As an example, the GNSS receiver 2110 may become a GlobalPositioning System (GPS) device.

The application ECU 2140 may be a microprocessor for providing aspecific application service. The application ECU may generate anoperation/message based on sensor information and a user input in orderto provide a service and transmit/receive the message by using the DSRCdevice processor. The sensor 2150 may obtain vehicle status and ambientsensor information. The human interface 2160 may receive a user's inputor display/provide the message through an interface such as an inputbutton or a monitor.

The V2X receiver 2200 includes a Global Navigation Satellite System(GNSS) receiver 2210, a DSRC radio 2220, a DSRC device processor 2230,an application Electronic Control Unit (ECU) 2240, a sensor 2250, and ahuman interface 2260. The aforementioned description of theconfiguration of the V2X transmitter 2100 is applied to theconfiguration of the V2X receiver 2200.

The DSRC radio and the DSRC device processor correspond to oneembodiment of a communication unit. The communication unit may performcommunication based on cellular communication technology such as 3GPPand Long Term Evolution (LTE).

FIG. 3 illustrates a configuration of a V2X system according to anembodiment of the disclosure.

As an embodiment, the V2X system of FIG. 3 may correspond to an ITSstation reference architecture defined in ISO 21217/EN302 665. In FIG. 3, the ITS station illustrates an example of an ITS station based on areference architecture. FIG. 3 illustrates a hierarchical architecturefor end-to-end communication. When a vehicle-to-vehicle message iscommunicated, the message is passed through each layer one layer down ina transmitting vehicle/ITS system and the message is delivered to anupper layer one layer up in a receiving vehicle/ITS system. Thedescription of each layer is as follows.

Application layer: The application layer may implement and supportvarious use cases. For example, an application may provide road safety,efficient traffic information, and other application information.

The application layer may classify and define the ITS application andprovide an end vehicle/user/infra-structure through the lower layer. Theapplication may be defined/applied for each user case or the use-casemay be grouped and defined/applied like the road safety, trafficefficiency, a local service, and infotainment. As an embodiment,application classification, the use-case, and the like may be updatedwhen a new application scenario is generated. Layer management maymanage and serve information related to an operation and a security ofthe application layer. The information and the service may bebidirectionally delivered and shared through an interface between MAMA(management entity and application layer and SA (interface betweensecurity entity and ITS-S applications) or service access point (SAP)(e.g., MA-SAP and SA-SAP). A request from the application layer to afacility layer or information delivery from the facility layer to theapplication layer may be performed through FA (interface betweenfacilities layer and ITS-S applications) (or FA-SAP).

Facilities layer: The facility layer may support various use-casesdefined in the application layer so as to effectively implement varioususe-cases. For example, the facility layer may perform applicationsupport, information support, and session/communication support.

The facility layer may basically support functions of a session layer, apresentation layer, and an application layer which are top three layers.The facility layer may additionally provide evolved facilities such asthe application support, the information support, and thesession/communication support for the ITS system. The facility means acomponent that provides functionality, information, and data.

The facilities may be classified into a common facility and a domainfacility. The common facility may provide a core service or functionrequired for a basic application set of the ITS and an operation of theITS station. For example, time management, position management, servicemanagement, and the like may be provided. The domain facility mayprovide a special service or function to the basic application set ofone or plural ITSs. For example, the domain facility may provideDEcentralized Notification Messages (DENM) management for Road HazardWarning applications (RHW). When the domain facility as an optionalfunction is not supported by the ITS station, the domain facility maynot be used.

Networking & Transport layer: The network/transport layer may configurea network for vehicle communication between homogeneous/heterogeneousnetworks by using various transport protocols and network protocols. Forexample, the networking/transport layer may provide Internet connectionand routing using an Internet protocol such as TCP/UDP+IPv6 or the like.Alternatively, the networking/transport layer may configure a vehiclenetwork by using a geographical position based protocol such as a basictransport protocol (BTP)/geo-networking.

The transport layer corresponds to a connection layer between servicesproviding upper layers (session layer, presentation layer, andapplication layer) and lower layers (network layer, data link layer, andphysical layer). The transport layer serves to manage data sent by auser to accurately arrive at a destination. At a transmitting side, thetransport layer may serve to split data into packets having anappropriate size for transmission for efficient data transmission. At areceiving side, the transport layer may serve to recombine the receivedpackets into an original file. As an embodiment, the transport protocolmay adopt TCP/UDP and a transport protocol for ITS such as VTS may beused.

The network layer may allocate a logical address and decide a packettransfer path. The network layer may receive a packet generated by thetransport layer and add a network header including the logical addressof the destination. As an example of a packet path design,unicast/broadcast may be considered between the vehicles, between thevehicle and a fixation station, and between fixation stations. As anembodiment, as the network protocol for the ITS, a protocol such asgeo-networking, IPv6 networking with mobility support, IPv6 overgeo-networking, or the like may be considered.

Access layer: The access layer may transmit messages/data received bythe upper layer through a physical channel. For example, the accesslayer may perform/support data communication based on IEEE 802.11 and/or802.11p standard-based communication technology, ITS-G5 wirelesscommunication technology based on physical transmission technology ofthe IEEE 802.11 and/or 802.11p standards, 2G/3G/4G (LTE)/5G wirelesscellular communication technology including satellite/broadband wirelessmobile communication, broadband terrestrial digital broadcastingtechnology such as DVB-T/T2/ATSC, GPS technology, IEEE 1609 WAVEtechnology, and the like.

The ITS system for vehicle communication and networking may beorganically designed in consideration of various access technologies,network protocols, and communication interfaces for providing varioususe-cases. Further, the role and the function of each layer may beenhanced or reinforced.

FIG. 4 illustrates a packet structure of a network/transport layeraccording to an embodiment of the disclosure.

FIG. 4 illustrates a packet structure of the network/transport layer,and the transport layer may generate a BTP packet and the network layermay generate a geo-networking packet. The geo-networking packetcorresponds to data of a logical link control (LLC) packet to beincluded in the LLC packet. The geo-networking packet may beencapsulated into the LLC packet. In an embodiment of FIG. 4 , the datamay include a message set and the message set may become a basic safetymessage.

The BTP is a protocol for transmitting the message such as the CAM orDENM generated by the facility layer to the lower layer. The BTP headeris constituted by A type and B type. An A type BTP header may include adestination port and a source port required for transmission/receptionfor interactive packet transmission. AB type BTP header may include thedestination port and destination port information required fortransmission for non-interactive packet transmission. The description ofa field/information included in the header is as follows.

Destination port: The destination port identifies a facility entitycorresponding to the destination of data (BTP-PDU) included in the BTPpacket.

Source port: as a field generated in the case of BTP-A type, indicates aport of a protocol entity of the facility layer in a source in which thecorresponding packet is transmitted. This field may have a size of 16bits.

Destination port Information: as a field generated in the case of BTP-Btype, may provide additional information when the destination port is amost well-known port. This field may have the size of 16 bits.

The geo-networking packet includes a basic header and a common headeraccording to the protocol of the network layer and optionally includesan extension header according to a geo-networking mode.

The basic header may be 32 bits (4 bytes). The basic header may includeat least one of a version field, a next header (NH) field, a lifetime(LT) field, and a remaining hop limit (RHL) field. The description ofthe fields included in the basic header is as follows. A bit sizeconfiguring each field is just an embodiment and may be modified.

Version (4 bits): A version field indicates a version of thegeo-networking protocol.

NH (4 bits): A next header (NH) field indicates a type of subsequentheader/field. When a field value is 1, the common header may be followedand when the field value is 2, a secured packet in which the security isconfigured may be followed.

LT (8 bits): A lifetime (LT) field indicates a maximum survival time ofthe corresponding packet.

RHL (8 bits): A remaining hop limit (RHL) field indicates a remaininghop limit. An RHL field value may be reduced by one for each forwardingon a GeoAdhoc router. When the RHL field value is 0, the correspondingpacket is not forwarded any longer.

The common header may be 64 bits (8 bytes). The common header mayinclude at least one of a next header (NH) field, a header type (HT)field, a header sub-type (HST) field, a header sub-type (HST) field, atraffic class (TC) field, a flags field, a payload length (PL) field,and a maximum hop limit (MHL) field. The description of each of thefields is as follows.

NH (4 bits): The next header (NH) field indicates the type of subsequentheader/field. When the field value is 0, the NH field may indicate “ANY”type which is not defined, when the field value is 1, the NH field mayindicate a BTP-A type packet, when the field value is 2, the NH fieldmay indicate a BTP-B type, and when the field value is 3, the NH fieldmay indicate an IP diagram of IPv6.

HT (4 bits): The header type field indicates a geo-networking type. Thegeo-networking type includes Beacon, GeoUnicast, GeoAnycast,GeoBroadcast, Topologically-Scoped Broadcast (TSB), and Location Service(LS).

HST (4 bits): The header sub type field indicates a detailed typetogether with the header type. As an embodiment, when the HT type is setto the TSB, the HST may indicate a single hop for the HST value of ‘0’and a multi-hop for the HST value of ‘1’.

TC (8 bits): The traffic class field may include Store-Carry-Forward(SCF), channel offload, and TC ID. The SCF field indicates whether tostore the packet when there is no neighbor to which the packet is to betransferred. The channel offload field indicates that the packet may betransferred to another channel in the case of a multi-channel operation.The TC ID field as a value allocated when transferring the packet in thefacility layer may be used for setting a contention window value in thephysical layer.

Flag (8 bits): The flag field indicates whether the ITS apparatus ismobile or stationary and as an embodiment, the flag field may becomelast 1 bit.

PL (8 bits): The payload length field indicates a data length subsequentto the geo-networking header in units of bytes. For example, in the caseof the geo-networking packet that carries the CAM, the PL field mayindicate the BTP header and the length of the CAM.

MHL (8 bits): The Maximum Hop Limit (MHL) field may indicate a maximumhopping number.

The LLC header is added to the geo-networking packet to generate the LLCpacket. The LLC header provides a function to distinguish and transmitIP data from geo-networking data. The IP data and the geo-networkingdata may be distinguished by Ethertype of SNAP. As an embodiment, whenthe IP data is transmitted, the Ethertype may be set to 0x86DD andincluded in the LLC header. As an embodiment, when the geo-networkingdata is transmitted, the Ethertype may be set to 0x86DC and included inthe LLC header. The receiver may verify the Ethertype field of the LLCpacket header and forward and process the packet to an IP data path or ageo networking path according to the value.

FIG. 5 illustrates a configuration of a V2X system according to anotherembodiment of the disclosure.

FIG. 5 illustrates a hierarchical architecture corresponding to anotherembodiment of the V2X system of FIG. 3 . As an embodiment, the NorthAmerican V2X system uses IEEE 802.11 PHY technology and MAC technology,and further may use the MAC technology of IEEE 1609.4. In thenetwork/transport layer technology, the technology of the IEEE802.2standard may be applied to an LLC block and the IEEE 1609.3 technologymay be applied to a WAVE short message protocol (WSMP). The facilitylayer may use a message set of a J2735 standard of SAE and theapplication layer may use an application defined for V2V, V2I, and V2Oin a J2945 standard.

The application layer may perform a function to implement and supportthe use-case. The application may be optionally used according to theuse-case. A system requirement of each use-case may be defined in theJ2945 standard. J2945/1 defines an application of V2V technology such asV2V safety communication.

A J2945/1 document defines applications including emergency electronicbrake lights (EEBL), forward crash warning (FCW), blind spot warning(BSW), lane change warning (LCW), intersection movement assist (IMA),and control loss warning (CLW). As an embodiment, FCW technology is V2Vsafety communication technology that warns of a collision with apreceding vehicle. When a vehicle equipped with the V2X communicationapparatus makes emergency stop or crashes, an FCW safety message may betransmitted in order to prevent a collision of a subsequent vehicle. Thesubsequent vehicle may receive FCW messages and alert a driver orperform such controls as speed deceleration or lane change. Inparticular, even when there is another vehicle between a stopped vehicleand a driving vehicle, it is possible to determine a state of thestopped through the FCW. The FCW safety message may include positionalinformation (latitude, longitude, and lane) of the vehicle, vehicleinformation (vehicle type, length, direction, speed), and eventinformation (stop, sudden stop, and slow down) and the information maybe generated by the request of the facility layer.

The facility layer may correspond to OSI layer 5 (session layer), layer6 (presentation layer), or layer 7 (application layer). The facilitylayer may generate the message set according to a situation in order tosupport the application. The message set may be defined in the J2735standard and described/decoded through ASN.1. The message set mayinclude a BasicSafetyMessage message, a MapData message, a SPAT message,CommonSafetyRequest message, an EmergencyVehicleAlert message, anIntersectionCollision message, a ProbeVehicleData message, aRoadSideAlert message, and a PersonalSafetyMessag message.

The facility layer collects the information to be transmitted from theupper layer to generate the message set. The message set may bedisplayed in an Abstract Syntax Notation 1 (ASN.1) scheme. The ASN.1 asa notation used to describe the data structure may also set anencoding/decoding rule. The ASN.1 does not depend on specific devices, adata representation scheme, programming languages, hardware platforms,and so on. The ASN.1 as a language for describing data regardless ofplatform is a joint standard between Consultative Committee onInternational Telegraphy and Telephony (CCITT) X.208 and InternationalOrganization for Standardization, (ISO) 8824.

The message set as a collection of messages related to V2X operationsand there is a message set appropriate to the context of the upperapplication. The message set may be expressed in a format of the dataframe and may include at least one element. Each element may include thedata frame or a data element.

The data frame represents two or more data sequences. The data frame maybecome a sequence structure of the data element or a sequence structureof the data frame. As an embodiment, DV_vehicleData as a data framestructure representing information of a vehicle may include a pluralityof data elements (for example, Height, Bumbers, mass, andtrailerweight). The data element defines a description of the dataelement. As an embodiment, an element called Height used in the dataframe is defined in DE_VehicleHeight and may express a height of thevehicle. As an embodiment, the height of the vehicle may be expressedfrom 0 to 127, and an LBS unit may be increased by 5 cm and be expressedup to 6.35 meters.

As an embodiment, a basic safety message (BasicSafetyMessage) may betransmitted. The BasicSafetyMessage as a most basic and importantmessage in the message set is used for periodically transmitting basicinformation of the vehicle. The corresponding message may includecoreData defined as BSMcoreData, PartII which is optional, and regionaldata. The coreData may include data elements including msgCnt, id, lat,long, elev, speed, deading, break, size, and the like. The coreData usesthe data elements to display a message count, ID, latitude, longitude,altitude, speed, direction, a brake, a vehicle size, and so on. Thecorresponding BSM may generally transmit information corresponding tothe coreData in a period of 100 msec (10 times per second).

The network/transport layer may correspond to OSI layer 3 (networklayer) and layer 4 (transport layer). A WAVE short message protocol(WSMP) may be used for transmitting a WAVE Short Message (WSM) deliveredby the upper layer. Additionally, an IPv6/TCP may be used for processingan IP signal in the related art. The LLC block may adopt the IEEE 802.2standard and may distinguish IP diagrams from WSM packets.

The access layer may correspond to OSI layer 1 (physical layer) and OSIlayer 2 (data link layer). The access layer may use PHY technology andMAC technology of IEEE 802.11 and additionally use MAC technology ofIEEE 1609.4 in order to support vehicle communication.

The security entity and the management entity may be connected andoperated in all intervals.

FIG. 6 illustrates a WSMP packet configuration according to anembodiment of the disclosure.

The network/transport layer of FIG. 5 may transmit a vehicle securitymessage such as the BSM via the WSMP. The WSMP is described in an IEEE1609.3 document and may also support the Ipv6 and the TCP/UDP in orderto additionally transmit the IP data.

The WSMP is a protocol for delivering the WAVE short message generatedin the ASN.1 scheme in the facility layer to the lower layer. Asillustrated in FIG. 6 , the WSMP packet includes the WSMP header and theWSM data including the message. The WSMP header includes a versionfield, a PSID field, an extension field, a WSM WAVE element ID field,and a length field.

The version field may be defined as a Wsmp Version field indicating anactual WSMP version of 4 bits and a reserved field of 4 bits. The PSIDfield as a provider service identifier may be allocated according to theapplication in the upper layer. The PSID field helps deciding anappropriate upper layer at the receiver side. The extension field is afield for extending the WSMP header and information including a channelnumber, data rate, transmit power used, and the like may be insertedinto the extension field. The WSMP WAVE element ID field may designate atype of transmitted WAVE short message. The length field may designate alength of the WSM data transmitted through a WSMLength field of 12 bitsin units of octets.

The LLC header provides a function to distinguish and transmit the IPdata from the WSMP data. The IP data and the WSMP data may bedistinguished by Ethertype of SNAP. As an embodiment, the LLC header andSNAP header structures may be defined in the IEEE 802.2 document. As anembodiment, when the IP data is transmitted, the Ethertype may be set to0x86DD and included in the LLC header. As an embodiment, when the WSMPdata is transmitted, the Ethertype may be set to 0x86DC and included inthe LLC header. The receiver may verify the Ethertype field of the LLCpacket header and forward and process the packet to an IP data path or aWSMP path according to the value.

FIG. 7 illustrates a conceptual internal architecture of an MAC sublayerperforming a multi-channel operation (MCO) according to an embodiment ofthe disclosure.

As an embodiment, the architecture of FIG. 7 may be included in theaccess layer of FIG. 5 or included in the MAC layer of the access layer.The MCO structure of FIG. 7 may include channel coordination in which achannel access is defined, channel routing in which operation processesof overall data and a management frame between PHY-MAC layers aredefined, Enhanced Dedicated Channel Access (EDCA) of deciding anddefining the priority of the transmission frame and a data buffer (orqueue) storing the frame received by the upper layer. A channelcoordination block is not illustrated in FIG. 7 and the channelcoordination may be performed by the entirety of an MAC sublayer of FIG.5 .

Channel coordination: As an embodiment, channel accesses to a controlchannel (CCH) and a service channel (SCH) may be controlled. A channelaccess coordination will be described below. As an embodiment, the Waveshort message (WSM) may be transmitted as (via) the CCH and the WSMand/or IP data may be transmitted as the SCH.

Data buffer (queue): The data buffer may store the data frame receivedfrom the upper layer according to defined access category (AC). In theembodiment of FIG. 3 , the data buffer may be provided for each AC.

Channel routing: A channel routing block may deliver data input in theupper layer to the data buffer. Transmission operation parameters suchas the channel number, the transmit power, and the data rate for thechannel coordination and the frame transmission may be called withrespect to a transmission request of the upper layer.

EDCA: As a scheme for guaranteeing QoS in the IEEE 802.11e MAC layer inthe related art is a contention based medium access scheme that dividesthe AC into four access categories (AC) according to a type of trafficand assigns different priorities for each category and allocatesdifferent parameters for each AC and gives more transmissionopportunities to traffic having a higher priority. An EDCA block maydesignate 8 priorities of 0 to 7 for data transmission including thepriority and data which reach the MAC layer may be mapped to four ACsaccording to the priority.

The control channel (CCH) refers to a radio channel used to exchangemanagement frames and/or WAVE messages. The WAVE message may be a WAVEshort message (WSM). The control channel (CCH) may represent a radiochannel mainly used for exchanging management messages or basic safetymessages. The service channel (SCH) is a radio channel used to provideservice and refers to any channel that is not the control channel.According to an embodiment, the control channel may be used tocommunicate system management messages, such as WAVE serviceadvertisements (WSAs), or WAVE short message protocol (WSMP) messages.The control channel may also be used for communication of WAVE ServiceAdvertisement (WSA) of Wave Short Message Protocol (WSMP) or ServiceAnnouncement Message (SAM) of Basic Transport Protocol(BTP)/Geo-networking. The SCH may be used for general-purposeapplication data communication, and such general-purpose applicationdata communication may be coordinated by service-related informationsuch as WSA.

WSA may also be referred to hereinafter as service advertisementinformation. WSA may provide information including an announcement ofthe availability of application-service. The WSA message may identifyand describe the application service and the channel accessible by theservice. According to an embodiment, WSA may include a header, serviceinformation, channel information, and WAVE routing advertisementinformation.

The service advertisement information for service access may be aperiodic message. As an embodiment, Co-operative Awareness Messages(CAM) may be periodic messages.

The V2X communication device may broadcast a Cooperative AwarenessMessage (CAM), a Decentralized Environmental Notification Message(DENM), or a Basic Safety Message (BSM).

The CAM is distributed in the ITS network and provides information forat least one of presence, location, and communication status of the ITSstation. DENM provides information for detected events. DENM may provideinformation for any driving situation or event detected by the ITSstation. For example, DENM may provide information for situations, suchas emergency electronic brakes, vehicle accidents, vehicle problems,traffic conditions, and the like. CAMs may be periodically broadcastedby the facility layer. As an embodiment, the WSA or SAM may be aperiodic message. WSA or SAM may be periodically broadcasted by thefacility layer.

Decentralized Environmental Notification Messages (DENM) may be eventmessages. Event messages may be triggered and transmitted by detectionof an event. Service messages may be sent to manage the session. In thefollowing embodiments, the event message may include a safetymessage/information. The service message may include a non-safetymessage/information.

As an embodiment, a Basic Safety Message (BSM) may be transmitted andreceived. The BSM message is the most basic message among the messagesdefined in the SAE J2735 standard and provides vehicle safety-relatedinformation. These BSM messages may be used in various applications forexchanging safety data regarding vehicle conditions. The BSM message maybe referred to as a basic safety message or a vehicle safety message.

Hereinafter, a geo-networking communication method for hybridcommunication is described.

The current V2X communication technology may perform geo-networkingcommunication for long range data delivery based on a multi-hop relayconcept. In the disclosure, the ad-hoc/direct/P2P communicationtechnology may include DSRC/802.11 access technology and/or LTE-sidelinktechnology, and these communication technologies may be used in eachhop. In the disclosure, an ad-hoc communication technology based on802.11p or cellular technology may be referred to as directcommunication. That is, direct communication may refer to communicationbetween terminals without intervention of a base station.

Geo-networking communications have a room for enhancement inreliability, delay, and efficiency. Since geo-networking communicationis based on a multi-hop relay, a communication failure of a single hopconstituting a multi-hop may cause a total communication failure.Additionally, as the number of hops increases, the required channelusage and delay may increase.

The hybrid communication may refer to a communication method in whichdirect communication technology and cellular communication technologyare used together. The direct communication technology may include aDSRC/802.11p access technology and/or an LTE-sidelink accesscommunication technology. Cellular communication technology includescellular-based access technology defined in 3GPP, such as 3G, 4G, LTE,and NR access technologies. When hybrid communication is used, thenumber of hops required for geo-networking communication may be reduced.

In order to utilize cellular communication technology for geo-networkingprotocols, additional technology may be required. For example, there maybe proposed such technologies as a network structure for geo-networkingusing hybrid communication, a use scenario for geo-networking usinghybrid communication, propagation of a forwarding algorithm type, a newpacket structure and SAP composition for geo-networking using hybridcommunication.

FIGS. 8(a) to 8(c) illustrate a geo-networking transmission methodaccording to an embodiment of the disclosure.

FIGS. 8(a) to 8(c) illustrate a geo-networking transmission method thatdoes not use hybrid communication. In the case of not using hybridcommunication, each op constitutes an entire multi-hoe route by usingad-hoc/direct/P2P communication technologies including 802.11p and LTEsidelinks.

In the disclosure, destination may indicate a geographic area or aspecific vehicle/V2X communication device/ITS station/router.

FIG. 8(a) illustrates a network architecture for geounicast, FIG. 8(b)illustrates a network architecture for geobroadcast, and FIG. 8(c)illustrates a network architecture for geoanicast.

FIGS. 9(a) to 9(c) illustrate a geo-networking transmission method usinghybrid communication according to an embodiment of the disclosure.

FIGS. 9(a) to 9(c) illustrate a geo-networking transmission method thatuses hybrid communication. In the case of using hybrid communication,each hop constitutes an entire multihop route by using a cellulartechnology including LTE uplink/downlink in addition to adhoc/direct/P2P communication technologies including 802.11p and LTEsidelink.

FIG. 9(a) illustrates a network architecture for geounicast using hybridcommunication, FIG. 9(b) illustrates a network architecture forgeobroadcast using hybrid communication, and FIG. 9(c) illustrates anetwork architecture for geoanycast using hybrid communication.

In FIGS. 9(a) to 9(c), some of the multiple hops may be relayed by basestations of cellular communication.

FIG. 10 illustrates a use scenario for geo-networking using hybridcommunication according to an embodiment of the disclosure.

FIG. 10 illustrates geo-networking using hybrid communication orgeo-networking that does not use hybrid communication, and illustrates acase in which all vehicles are outside the coverage of a cellular basestation. In the embodiment of FIG. 10 , multi-hop communication consistsof ad hoc communications.

FIGS. 11(a), and 11(b) illustrate a use scenario for geo-networkingusing hybrid communication according to an embodiment of the disclosure.

FIGS. 11(a), and 11(b) illustrate geo-networking using hybridcommunication, and illustrates a case in which all vehicles are withinthe coverage of a cellular base station. In the embodiment of FIGS.11(a), and 11(b), multi-hop communication may be performed by cellularcommunication or may be replaced by cellular communication.

FIG. 11(a) illustrates a case in which both a transmission vehicle and atarget vehicle are included in the coverage of one cellular basestation. Multi-hop communication is not performed by a plurality ofvehicles, but may be relayed by a base station.

FIG. 11(b) illustrates a case where a transmission vehicle and adestination vehicle are each included in the coverage of a differentcellular base station. Multi-hop communication is not performed by aplurality of vehicles, but may be relayed by a base station. That is,multi-hop communication may be relayed by a plurality of base stations.

FIG. 12 illustrates a usage scenario for geo-networking using hybridcommunication according to an embodiment of the disclosure.

FIG. 12 illustrates a case in which some of the vehicles performingmulti-hop communication are included in cellular base station coverage.Multihop communication may be relayed by a plurality of vehicles and acellular base station.

For a geo-networking transmission method using hybrid communication, aplurality of forwarding algorithms may be used. A brief description ofthe forwarding algorithms is as follows.

(Non-area) Greedy Forwarding Algorithm (GF): The sender uses thelocation of the destination and the neighbor. The sender may select areceiver with the smallest distance to the destination among neighboringreceivers stored in the location table as the forwarder. The senderunicasts GN (GeoNetwork) packets to the selected forwarder.

(Non-area) Contention based Forwarding Algorithm (CBF): The sender doesnot use the location of the destination. The sender broadcasts GNpackets. Receivers set a timer. The time length of the timer isinversely proportional to the forward progress. Forward progress isdefined as the difference between the sender's distance to thedestination and the receiver's distance. A receiver whose timer hasexpired broadcasts reception GN packets, and other receivers that havereceived the broadcast stop the timer and delete the stored GN packet.

Simple GeoBroadcast Forwarding Algorithm: is used sed for geobroadcast.The sender broadcasts GN packets. The receivers located inside or at theboundary of the target area broadcast reception GN packets withoutduplicate detection. This algorithm may be considered as a rule forspecial cases.

Area Contention-based Forwarding Algorithm: is used for geobroadcast orgeoanycast. This is the same as non-area contention-based forwardingexcept that forward progress is defined as the distance between thereceiver and the sender, and receivers located inside or at the boundaryof the target area broadcast reception GN packets without duplicatedetection. This algorithm may be considered as a rule for special cases.

Area Advanced Forwarding Algorithm: An enhanced regional CBF in whichgreedy forwarding and regional CBF are used simultaneously. CBF appliesonly to receivers located outside the sectorial area. The receiver bygreedy forwarding forwards the GN packet by greedy forwarding, and thereceiver by the CBF algorithm forwards the GN packet by CBF algorithm.

Described below is a modified forwarding algorithm using hybridcommunication.

FIG. 13 illustrates a basic forwarding algorithm using hybridcommunication when a destination exists in the direct communicationrange of a sender.

When the destination is within the direct communication range of thesender, the sender may directly transmit the GN packet to thedestination. In this case, even when both the sender vehicle and thedestination vehicle are within the communication coverage of thecellular base station, inter-vehicle communication may be performed bydirect ad-hoc communication.

FIG. 14 illustrates a basic forwarding algorithm using hybridcommunication when a sender exists within the coverage of a cellularbase station.

When the sender is within the communication range of the cellular basestation, the sender may transmit a GN packet to the base station. Inthis case, cellular communication technology may be used. The GN packetmay be forwarded directly or indirectly by the base station within thesmallest distance to the destination of the GN packet.

FIG. 15 illustrates a basic forwarding algorithm using hybridcommunication when a destination exists within the coverage of acellular base station.

The destination may exist within the coverage of the cellular basestation that receives the GN packet. The base station may send packetsdirectly to the destination without additional relay. When the transporttype of the GN packet is geounicast, the base station may unicast the GNpacket to the target ITS station. When the transport type of the GNpacket is geobroadcast, the base station may broadcast the GN packet tothe target area. When the transport type of the GN packet is geoanycast,the base station may unicast the GN packet to any ITS station in thetarget area.

Described below is an enhanced greedy forwarding algorithm using hybridcommunication.

FIG. 16 illustrates a use scenario of a first embodiment (EGF1) of anenhanced greedy forwarding algorithm according to an embodiment of thedisclosure.

The sender may transmit a packet by using information for the locationof the destination and neighbors and whether the neighbors are capableof hybrid communication. The capability of hybrid communicationindicates whether a neighbor V2X communication device may not onlyperform direct communication but also communicate with the mobilecellular base station. For example, hybrid communication capability maymean the ability to utilize an LTE-Uu interface or any other cellularcommunication technology (3GPP defined cellular-based accesstechnologies including 3G, 4G, LTE, and NR access technologies).

The sender may select, as a forwarder, a receiver having the smallestgeographic distance to the destination among receivers capable of hybridcommunication. If no receiver capable of hybrid communication exists inthe vicinity, this algorithm may operate according to the originalgreedy forwarding algorithm.

The sender unicasts the GN packet to the selected forwarder. Thisalgorithm may be implemented with minimal modifications to the originalgreedy algorithm.

The performance of hybrid communication may be collected by CAM or BSM.Required fields of the CAM and BSM for delivering hybrid communicationcapability information may be defined as follows.

Table 1 shows data elements of “hybridCapability”, as an embodiment ofhybrid performance information according to an embodiment of thedisclosure. The hybrid performance information may identify theperformance/availability of hybrid communication.

TABLE 1 Descriptive Name hybridCapability Identifier DataType_xxx ASN.1HybridCapability ::= Boolean representation Definition This DE (DataElement) identifies the capability of hybrid communication. “1” meansthat the vehicle is capable of hybrid communication, and “0” means thatthe vehicle is not capable of hybrid communication. Unit N/A

Table 2 shows data elements of “cellularCommunicationCapability”, as anembodiment of hybrid performance information according to an embodimentof the disclosure. The cellular communication capability information mayidentify the capability/availability of cellular communication.

TABLE 2 Descriptive Name cellularCommunicationCapability IdentifierDataType_xxx ASN.1 cellularCommunicationCapability ::= Booleanrepresentation Definition This DE (Data Element) identifies thecapability of cellular communication. “1” means that the vehicle iscapable of cellular communication, and “0” means that the vehicle is notcapable of cellular communication. Unit N/A

Table 3 shows data elements of “equippedAccessTechnologies”, as anembodiment of hybrid performance information according to an embodimentof the disclosure. The equipped access technology information mayidentify the access layer technology equipped in the vehicle/V2Xcommunication device.

TABLE 3 Descriptive Name equippedAccessTechnologies IdentifierDataType_xxx ASN.1 equippedAccessTechnologies ::= ENUMERATED {representation DSRC (0), LTE_PC5 (1), LTE_Uu (2), . . . } DefinitionThis DE (Data Element) identifies the access layer technologies that thevehicle is equipped with. Unit N/A

FIGS. 17(a), and 17(b) illustrate a configuration of a CAM according toan embodiment of the disclosure. FIG. 17(a) illustrates an embodiment inwhich a “hybridCapability” field corresponding to hybrid performanceinformation is included in a basic container of a CAM. FIG. 17(b)illustrates an embodiment in which a “hybridCapability” fieldcorresponding to hybrid performance information is included in an LFcontainer of a CAM. FIGS. 17(a), and 17(b) illustrate an embodiment, inwhich a hybrid capability field may be included in a container/fielddifferent from that of FIGS. 17(a), and 17(b).

In FIGS. 17(a), and 17(b), a description of headers and containersincluded in the CAM is as follows.

-   -   ITS PDU header: This is a common message header for application        layer messages and facility layer messages. This is included as        a message header at the beginning of the ITS message. The DF        (data frame) may include the following information.    -   protocol Version (protocol version information): indicates the        version of the ITS message and/or communication protocol.    -   messageID (message ID information): indicates the type of ITS        message (e.g., CAM, DENM).    -   stationID (station ID information): The identifier of the ITS        station generating the ITS message.

Basic Container: provides basic information for ITS-S. The basiccontainer may exist for CAMs created by all ITS stations implementing CAbasic services. The basic container may include the followinginformation.

-   -   stationType (station type information): type of ITS-S    -   referencePostion (reference position information): In CAM        generation, the latest geographic position of ITS-S obtained by        CA basic service. Or, this indicates the geographic position of        the ITS-S at the time of generating the corresponding CAM.

HF container: The HF container may contain dynamic status informationfor the ITS station vehicle, such as heading or speed. The HF containermay contain all fast-changing state information. Some items in the HFcontainer may be optional for CAM and may be included as needed.

LF container: The LF container may contain static or slow-changingvehicle data, such as the state of an exterior light. The LF containeritems may be optional for CAM and may be included as needed.

Special vehicle container: may provide additional status information. Inroad traffic, a vehicle ITS-S that performs a special role, such aspublic transportation, may provide additional status information throughthe special vehicle container. Special vehicle container items may beoptional for CAM and may be included as needed.

FIGS. 18(a), and 18(b) illustrate a configuration of a BSM according toan embodiment of the disclosure.

FIG. 18(a) illustrates an embodiment in which a “hybridCapability” fieldcorresponding to hybrid performance information is included in a coredata container of a BSM. FIG. 18(b) illustrates an embodiment in which a“hybridCapability” field corresponding to hybrid performance informationis included in a part II container of a BSM. FIGS. 18(a), and 18(b)illustrate an embodiment, in which a hybrid capability field may beincluded in a container/field different from that of FIGS. 18(a), and18(b).

In FIGS. 18(a), and 18(b), a description of containers included in theBSM is as follows.

CoreData container: This data frame may include a critical core dataelement that is required whenever a BSM is issued. For example, the coredata container may include a message count, a message ID, basicinformation for a vehicle, position and kinetic information, and thelike. Some items of the core data container may be optional for BSM andmay be included as needed.

Part II container: Part 2 data items may be optional for BSM and may beincluded as needed. The Part 2 container may contain extensioninformation for vehicle safety, special vehicles, and supplementalvehicles.

Regional container: The regional container may include region-specificextension information.

The hybrid communication capability information described above isregularly broadcast and may be shared with neighbors. When the senderstarts transmitting GN packets by geo-networking, the vehicle mayalready be aware of the hybrid communication capabilities of itsneighbors.

FIG. 19 illustrates a use scenario of a second embodiment (EGF2) of anenhanced greedy forwarding algorithm according to another embodiment ofthe disclosure.

The sender may transmit a packet by using information for the locationof the destination and neighbors and the hybrid communication capabilityof the neighbors. Also, the sender may transmit a packet by usinginformation for whether a neighboring vehicle capable of hybridcommunication exists within the range of cellular communication.

The sender may select, as a forwarder, a receiver having the smallestgeographic distance to the destination among receivers capable of hybridcommunication. Further, the sender may select, as a forwarder, areceiver having the smallest geographic distance to the destination fromamong receivers capable of hybrid communication within the range ofcellular communication. If no receiver capable of hybrid communicationexists within the cellular communication range, this algorithm mayoperate according to the original greedy forwarding algorithm.

Whether a vehicle capable of hybrid communication is within cellularcommunication range may be collected by the CAM or BSM. The requiredfields of CAM and BSM for this may be defined as follows.

Table 4 shows data elements of “cellularInRange” as an embodiment ofinformation indicating whether it is within the cellular communicationrange according to an embodiment of the disclosure. The cellular inrange information indicates whether a vehicle capable of hydridecommunication is within the cellular communication range.

TABLE 4 Descriptive Name cellularInRange Identifier DataType_xxx ASN.1CellularInRange ::= Boolean representation Definition This DE (DataElement) identifies whether the hybrid communication capable vehicle isin rage. “1” means that the vehicle is in range, and “0” means that thevehicle is not in rage. Unit N/A

FIG. 20 illustrates a configuration of a CAM according to an embodimentof the disclosure. FIG. 20 illustrates an embodiment in which cellularrange information is included in an HF container. FIG. 20 illustrates anembodiment, in which the cellular range field may be included in acontainer/field different from that of FIG. 20 . FIG. 21 illustrates aconfiguration of a BSM according to an embodiment of the disclosure.FIG. 21 illustrates an embodiment in which cellular range information ofa BSM is included in a Part 2 container. FIG. 21 illustrates anembodiment, in which the cellular range field may be included in acontainer/field different from that of FIG. 21.

The hybrid communication capability information described above isregularly broadcast and may be shared with neighbors. When the senderstarts transmitting GN packets by geo-networking, the vehicle mayalready be aware of the hybrid communication capabilities of itsneighbors.

FIG. 22 is a flowchart illustrating a forwarding algorithm of EGF1and/or EFG2 according to an embodiment of the disclosure.

The sender 22010 may receive a CAM or BSM from neighboring vehicles22020 and 22030. The CAM or BSM may include at least one of locationinformation, hybrid capability information, and cellular rangeinformation, as in the embodiments of FIGS. 16 to 21 .

The sender has at least one of current, location information, hybridperformance information, or cellular range information for neighboringvehicles. The sender transmits a packet based on at least one oflocation information, hybrid capability information, or cellular rangeinformation for neighboring vehicles. The sender transmits the GN packetbased on the EFG1 or EGF2 algorithm.

Described below is a sender management/managed forwarding algorithmusing hybrid communication.

FIG. 23 illustrates a use scenario of a first embodiment (SMF1) of asender managed forwarding algorithm according to an embodiment of thedisclosure.

The sender uses the location information for the destination andneighbors, and uses the information for whether the neighbors arecapable of hybrid communication.

The sender selects a receiver having the most reliable communicationlink with the sender among receivers capable of hybrid communication asa forwarder. When it is difficult or impossible to determine the qualityof the communication link with the receiver, the receiver closest to thesender may be selected as the forwarder. If there is no receiver capableof hybrid communication, this algorithm may be performed as an originalgreedy forwarding algorithm.

The sender may unicast the GN packet to the selected forwarder.

The SMF1 algorithm may enhance the reliability of greedy forwarding.When the receiver closest to the sender is selected, communicationreliability may be enhanced as compared to a case where a receiver farfrom the sender is selected. Since a receiver at a close distance isselected, a larger number of hops are required at the same distance,thereby increasing latency. However, since a cellular network is usedaccording to the disclosure, the increase in the number of hops andlatency may be neglected.

FIG. 24 illustrates a use scenario of a second embodiment (SMF2) of asender managed forwarding algorithm according to an embodiment of thedisclosure.

The sender uses the location information for the destination andneighbors, and uses the information for whether the neighbors arecapable of hybrid communication. Further, the sender may use informationfor whether neighbors capable of hybrid communication are within acellular communication range.

The sender selects a receiver having the most reliable communicationlink with the sender from among receivers capable of hybridcommunication within the cellular communication range as a forwarder.When it is difficult or impossible to determine the quality of thecommunication link with the receiver, the receiver closest to the sendermay be selected as the forwarder. If there is no receiver capable ofhybrid communication, this algorithm may be performed as an originalgreedy forwarding algorithm.

The sender may unicast the GN packet to the selected forwarder.

Before starting the algorithm of SMF1 and SMF2, the sender may gatherrequired information of neighboring vehicles, as in the above-describedembodiments of EGF1 and EFG2.

Hereinafter, an enhanced contention-based forwarding algorithm forhybrid communication is described.

FIG. 25 illustrates a use scenario of a first embodiment (EFBF1) of anenhanced contention-based forwarding algorithm for hybrid communication.

In this embodiment, the sender does not use the location information forthe destination and neighbors, nor does it use information about whetherthe neighbors are capable of hybrid communication. The sender broadcastsGN packets. The receiver sets a timer.

The length of time of the timer may be a value based on the capabilityof hybrid communication. The time length of the timer is a valuedepending on the capability of hybrid communication plus another valueinversely proportional to the forward progress. Forward progress isdefined as the difference between the sender's distance to thedestination and the receiver's distance. The GN packet received by thereceiver whose timer has expired is broadcast. The other receivers thathave received this GN packet may stop the timer and drop the GN packet.

The timer time at which the packet is buffered in the buffer may bedetermined as in Equation 1.

$\begin{matrix}{{TO\_ CBF} = {{{TO\_ CBF}{\_ MAX}} + {\frac{{{TO\_ CBF}{\_ MIN}} - {{TO\_ CBF}{\_ MAX}}}{DIST\_ MAX} \times {PROG}} + {{WT\_ HYB}{\_ CAPA}}}} & \lbrack {{Equation}1} \rbrack\end{matrix}$

TO_CBF_MIN: Minimum duration during which the CBF packet buffer isbuffered

TO_CBF_MAX: Maximum duration during which the CBF packet buffer isbuffered

PROG: indicates forwarding progress. For example, it may be thedifference between the distance of the sender to the destination and thedistance of the receiver. The value of PROG may be 0 or more and may benot more than DIST_MAX.

DIST_MAX: theoretical maximum range of non-cellular V2V directcommunication

WT_HYB_CAPA: the value for waiting time depending on the capability ofhybrid communication. When the receiver is capable of hybridcommunication, the hybrid communication availability time value may beset to 0. When the receiver is unable to perform hybrid communication,the hybrid communication availability time value may be set toTO_CBF_MAX.

In the embodiment of FIG. 25 , the timer time length may be determinedas follows. In the embodiment of FIG. 25 , it is assumed thatTO_CBF_MIN=500 ms, TO_CBF_MAX=3 s, and DIST_MAX=100 m. The distance tothe destination is assumed to be sender=200 m, vehicle (1)=180 m,vehicle (2)=150 m, vehicle (3)=120 m, vehicle (4)=160 m, and vehicle(5)=190 m. In this case, the length of the timer time for each vehiclemay be determined as in Table 5.

TABLE 5 Time length of vehicle PROG WT_HYB_CAPA timer (TO_CBF) (1) 20 33 + (−2.5/100) × 20 + 3 = 5.5 s (2) 50 3 3 + (−2.5/100) × 50 + 3 = 4.75s (3) 80 0 3 + (−2.5/100) × 80 + 0 = 1 s (4) 40 0 3 + (−2.5/100) × 40 +0 = 2 s (5) 10 0 3 + (−2.5/100) × 10 + 0 = 2.75 s

Vehicle 3 is the closest to the destination among receivers capable ofcellular communication. Thus, vehicle 3 has a minimum waiting time forGN packet forwarding.

FIG. 26 is a view illustrating an execution operation of an ECVF1algorithm according to the embodiment of FIG. 25 . In FIG. 26 , thesender vehicle 26010 broadcasts the GN packet and deletes thetransmitted GN packet. Each of the neighboring vehicles 26020 to 26060sets a timer. The timer waiting time is as shown in Table 5. Neighboringvehicle 3 26040 broadcasts a GN packet after a timer waiting time of 1s. Other neighboring vehicles that have set a timer as neighboringvehicle 3 delete the same packet and stop the timer when receiving thepacket transmitted by neighboring vehicle 3. The vehicle 26070 toperform the next hop may set a timer and perform forwarding.

FIG. 27 illustrates a use scenario of a second embodiment (EFBF2) of anenhanced contention-based forwarding algorithm for hybrid communication.

In this embodiment, the sender does not use the location information forthe destination and neighbors, nor does it use information about whetherthe neighbors are capable of hybrid communication. The sender broadcastsGN packets. The receiver sets a timer.

The time length of the timer may be a value based on the capability ofthe hybrid communication and the current availability of the hybridcommunication. The time length of the timer is a value depending on thecapability and current availability of hybrid communication plus anothervalue inversely proportional to the forward progress. Forward progressis defined as the difference between the sender's distance to thedestination and the receiver's distance. The GN packet received by thereceiver whose timer has expired is broadcast. The other receivers thathave received this GN packet may stop the timer and drop the GN packet.

The timer time at which the packet is buffered in the buffer may bedetermined as in Equation 2.

$\begin{matrix}{{TO\_ CBF} = {{{TO\_ CBF}{\_ MAX}} + {\frac{{{TO\_ CBF}{\_ MIN}} - {{TO\_ CBF}{\_ MAX}}}{DIST\_ MAX} \times {PROG}} + {{WT\_ HYB}{\_ CAPA}} + {{WT\_ HYB}{\_ Coverage}}}} & \lbrack {{Equation}2} \rbrack\end{matrix}$

TO_CBF_MIN: Minimum duration during which the CBF packet buffer isbuffered

TO_CBF_MAX: Maximum duration during which the CBF packet buffer isbuffered

PROG: indicates forwarding progress. For example, it may be thedifference between the distance of the sender to the destination and thedistance of the receiver. The value of PROG may be 0 or more and may benot more than DIST_MAX.

DIST_MAX: theoretical maximum range of non-cellular V2V directcommunication

WT_HYB_CAPA: the value for waiting time depending on the capability ofhybrid communication. When the receiver is capable of hybridcommunication, the hybrid communication availability time value may beset to 0. When the receiver is unable to perform hybrid communication,the hybrid communication availability time value may be set toTO_CBF_MAX.

WT_HYB_Coverage: the value for waiting time based on the currentavailability of hybrid communication. When the receiver is within thecoverage of the cellular base station, the hybrid coverage waiting timevalue may be set to 0. When the receiver is not within the coverage ofthe cellular base station, the hybrid coverage waiting time value may beset to TO_CBF_MAX.

In the embodiment of FIG. 27 , the timer time length may be determinedas follows. In the embodiment of FIG. 25 , it is assumed thatTO_CBF_MIN=500 ms, TO_CBF_MAX=3 s, and DIST_MAX=100 m. The distance tothe destination is assumed to be sender=200 m, vehicle (1)=180 m,vehicle (2)=150 m, vehicle (3)=120 m, vehicle (4)=160 m, and vehicle(5)=190 m. In this case, the length of the timer time for each vehiclemay be determined as in Table 6.

TABLE 6 Time length of vehicle PROG WT_HYB_CAPA WT_HYB_Coverage timer(TO_CBF) (1) 20 3 3 3 + (−2.5/100) × 20 + 3 + 3 = 8.5 s (2) 50 3 3 3 +(−2.5/100) × 50 + 3 + 3 = 7.75 s (3) 80 0 3 3 + (−2.5/100) × 80 + 0 + 3= 4 s (4) 40 0 0 3 + (−2.5/100) × 40 + 0 + 0 = 2 s (5) 10 0 0 3 +(−2.5/100) × 10 + 0 + 0 = 2.75 s

Vehicle 4 is the closest to the destination among receivers capable ofcellular communication within cellular communication coverage. Thus,vehicle 4 has a minimum waiting time for GN packet forwarding. FIG. 28is a view illustrating an execution operation of an ECVF2 algorithmaccording to the embodiment of FIG. 26 .

In FIG. 28 , the sender vehicle 28010 broadcasts the GN packet anddeletes the transmitted GN packet. Each of the neighboring vehicles28020 to 28060 sets a timer. The timer waiting time is as shown in Table6. Neighboring vehicle 4 22050 broadcasts a GN packet after a timerwaiting time of 2 s. Other neighboring vehicles that have set a timer asneighboring vehicle 4 delete the same packet and stop the timer whenreceiving the packet transmitted by neighboring vehicle 4. The vehicle22070 to perform the next hop may set a timer and perform forwarding.

FIG. 29 illustrates a use scenario of a Combined Sender-based andContention-based Forwarding (CSCF) algorithm according to an embodimentof the disclosure.

The sender uses the destination and the location of their neighbors. Thesender may select at least one receiver having the smallest distance tothe destination as a forwarder. The sender may unicast or multicast theGN packet with at least one selected forwarder.

The receiver sets a timer. The length of the timer may be inverselyproportional to a forwarding progress corresponding to a differencebetween the distance of the sender to the destination and the distanceof the receiver. When the timer expires, the receiver broadcasts thereceived GN packet, and other receivers stop the timer and delete the GNpacket.

In the embodiment of FIG. 29 , the timer time length may be determinedas follows. In the embodiment of FIG. 25 , it is assumed thatTO_CBF_MIN=500 ms, TO_CBF_MAX=3 s, and DIST_MAX=100 m. The distance tothe destination is assumed to be sender=200 m, vehicle (1)=180 m,vehicle (2)=150 m, vehicle (3)=120 m, vehicle (4)=160 m, and vehicle(5)=190 m. In this case, the length of the timer time for each vehiclemay be determined as in Table 7.

TABLE 7 Time length of vehicle PROG timer (TO_CBF) (2) 50 3 + (−2.5/100)× 50 = 1.75 s (3) 80 3 + (−2.5/100) × 80 = 1 s (4) 40 3 + (−2.5/100) ×40 = 2 s

Vehicle 3 is the closest to the destination among receivers withindirect ad-hoc communication coverage. Thus, vehicle 3 has a minimumwaiting time for GN packet forwarding. FIG. 30 is a view illustrating anexecution operation of a CSCF algorithm according to the embodiment ofFIG. 29 .

In FIG. 30 , the sender vehicle 30010 broadcasts the GN packet anddeletes the transmitted GN packet. Each of the neighboring vehicles30020 to 30060 sets a timer. The timer waiting time is as shown in Table7. Neighboring vehicle 3 22040 broadcasts a GN packet after a timerwaiting time of 1 s. The other neighboring vehicles that have set atimer as neighboring vehicle 3 delete the same packet and stop the timerwhen receiving the packet transmitted by neighboring vehicle 3. Thevehicle 30070 to perform the next hop may set a timer and performforwarding.

FIG. 31 illustrates a first embodiment of an Enhance CombinedSender-based and Contention-based Forwarding (ECSCF) algorithm usinghybrid communication according to an embodiment of the disclosure.

The sender uses the destination and the location of their neighbors. Thesender may select at least one receiver having the smallest distance tothe destination as a forwarder. The sender may unicast or multicast theGN packet with at least one selected forwarder.

The receiver sets a timer. The length of the timer may be inverselyproportional to a forwarding progress corresponding to a differencebetween the distance of the sender to the destination and the distanceof the receiver. Further, as in the above-described embodiment, thelength of the timer may be based on the capability of hybridcommunication. When the timer expires, the receiver broadcasts thereceived GN packet, and other receivers stop the timer and delete the GNpacket.

In the embodiment of FIG. 31 , the timer time length may be determinedas follows. In the embodiment of FIG. 31 , it is assumed thatTO_CBF_MIN=500 ms, TO_CBF_MAX=3 s, and DIST_MAX=100 m. The distance tothe destination is assumed to be sender=200 m, vehicle (1)=180 m,vehicle (2)=150 m, vehicle (3)=120 m, vehicle (4)=160 m, and vehicle(5)=190 m. In this case, the length of the timer time for each vehiclemay be determined as in Table 8.

TABLE 8 Time length of vehicle PROG WT_HYB_CAPA timer (TO_CBF) (2) 50 03 + (−2.5/100) × 50 + 0 = 1.75 s (3) 80 3 3 + (−2.5/100) × 80 + 3 = 4 s(4) 40 0 3 + (−2.5/100) × 40 + 0 = 2 s

Vehicle 2 is the closest to the destination among receivers capable ofcellular communication. Thus, vehicle 2 has a minimum waiting time forGN packet forwarding. The flowchart for the embodiment of FIG. 31 issimilar to ECBF1 and/or CSCF described above.

FIG. 32 illustrates a second embodiment of an Enhance CombinedSender-based and Contention-based Forwarding (ECSCF) algorithm usinghybrid communication according to an embodiment of the disclosure.

The sender uses the destination and the location of their neighbors. Thesender may select at least one receiver having the smallest distance tothe destination as a forwarder. The sender may unicast or multicast theGN packet with at least one selected forwarder.

The receiver sets a timer. The length of the timer may be inverselyproportional to a forwarding progress corresponding to a differencebetween the distance of the sender to the destination and the distanceof the receiver. Further, as in the above-described embodiment, thelength of the timer may be based on the hybrid communication capabilityand the current communication availability. When the timer expires, thereceiver broadcasts the received GN packet, and other receivers stop thetimer and delete the GN packet.

In the embodiment of FIG. 32 , the timer time length may be determinedas follows. In the embodiment of FIG. 32 , it is assumed thatTO_CBF_MIN=500 ms, TO_CBF_MAX=3 s, and DIST_MAX=100 m. The distance tothe destination is assumed to be sender=200 m, vehicle (1)=180 m,vehicle (2)=150 m, vehicle (3)=120 m, vehicle (4)=160 m, and vehicle(5)=190 m. In this case, the length of the timer time for each vehiclemay be determined as in Table 9.

TABLE 9 Time length of vehicle PROG WT_HYB_CAPA WT_HYB_Coverage timer(TO_CBF) (2) 50 0 3 3 + (−2.5/100) × 50 + 0 + 3 = 4.75 s (3) 80 3 3 3 +(−2.5/100) × 80 + 3 + 3 = 7 s (4) 40 0 0 3 + (−2.5/100) × 40 + 0 + 0 = 2s

Vehicle 4 is capable of cellular communication and is the closest to thedestination among receivers within the range of cellular communication.Thus, vehicle 4 has a minimum waiting time for GN packet forwarding. Theflowchart for the embodiment of FIG. 32 is similar to ECBF1 and/or CSCFdescribed above.

Hereinafter, propagation of the forwarding algorithm type is described.

In the above-described embodiments, receivers may only know whether thereceived GN packet has been delivered by unicast or broadcast. Based onthis knowledge, the forwarder forwards (e.g., greedy forwarding) the GNpacket by unicast (e.g., greedy forwarding) when the received packet isreceived by unicast, and forwards (e.g., contention-based forwarding)the GN packet by broadcast when the received packet is received bybroadcast.

In contrast, when the forwarding algorithm as in the above-describedembodiment is used, there may be needed a method for maintaining theoriginally intended algorithm for entire multi-hop routing. This isbecause the first sender selects the optimal forwarding algorithmconsidering, e.g., network traffic and priority of GN packets.

Table 10 shows the forwarding algorithm proposed in the disclosure.

TABLE 10 Unicast Multicast Broadcast EGF1 CSCF ECBF1 EGF2 ECSCF1 ECBF2SMF1 ECSCF2 SMF2

As shown in Table 10, simply recognizing the transmission method ofunicast, multicast, or broadcast may be insufficient to maintain theintended forwarding algorithm. However, if the forwarder is able to findan optimal forwarding algorithm, the forwarder may change the forwardingalgorithm. The type of forwarding algorithm intended by the originalsender may need to be conveyed through the GN packet. The packetstructure and SAP for delivering forwarding algorithm type informationis described below.

FIG. 33 illustrates a configuration of a common header of ageo-networking packet according to an embodiment of the disclosure.

A description of each field included in the common header of FIG. 33 isas follows.

NH: The network header field identifies the type of the geo-networkingheader immediately following the geo-networking header.

HT: The header type field identifies the type of the geo-networkingheader. The geo-networking header type may include at least one of ANY,BEOCON, GEOUNICAST, GEOANYCAST, GEOBROADCAST, TSB, or LS.

HST: The header subtype field identifies the subtype of thegeo-networking header. The subtype of the geo-networking header mayinclude at least one of GEOANYCAST_CIRCLE, GEOANYCAST_RECT,GEOANYCAST_ELIP, GEOBROADCAST_CIRCLE, GEOBROADCAST_RECT,GEOBROADCAST_ELIP, SINGLE_HOP, MULTI_HOP, LS_REQUEST, LS_REPLY, orUNSPECIFIED.

TC: The traffic class field represents a traffic class indicating afacility-layer request for a packet transport.

Flags: Bit 0 may indicate whether the ITS-S is mobile or stationary (GNprotocol constant itsGnlsMobile). Bits 1 to 7 are reserved.

PL: The payload length field indicates the length of the geo-networkingpayload.

MHL: The maximum hop limit field indicates the maximum hop limit.

FIG. 34 illustrates a configuration of a common header of ageo-networking packet according to an embodiment of the disclosure.

FIG. 34 includes a forwarding algorithm type field and a sub-forwardingtype field. No duplicate description of the fields described in FIG. 33is given.

FT: The forwarding algorithm type field identifies the type offorwarding algorithm. The forwarding algorithm type may include at leastone of EGF1, EGF2, SMF1, SMF2, ECBF1, ECBF2, CSCF, ECSCF1, or ECSCF2.

SFT: The sub-forwarding type field identifies the sub-type of theforwarding algorithm. The sub-penetration may include at least one ofUNSPECIFIED for EGF1, EGF2, SMF1, SMF2, ECBF1, and ECBF2, an integer (2. . . 255) for CSCF, ECSCF1, or ECSCF2 indicating the number ofreceivers per sender.

At least one of FT information or SFT information may be included in anarbitrary position of the packet. For example, at least one of FTinformation or SFT information may be included in a reserved field ofthe geo-networking common header.

FIG. 35 illustrates propagation of forwarding type information accordingto an embodiment of the disclosure.

The sender 35010 forwards the GN packet with forwarding algorithm A. Thetype of forwarding algorithm may be included in the packet as describedabove.

Forwarder 1 35020 has difficulty in finding the optimal forwardingalgorithm or does not try to find another forwarding algorithm.Forwarder 1 305020 forwards the GN packet using the forwarding algorithmA applied to the received packet. The type of forwarding algorithm maybe included in the packet as described above.

Forwarder 2 35030 may find an optimal forwarding algorithm and may findother forwarding algorithms. Forwarder 2 35030 may forward the GN packetwith a new forwarding algorithm B. The type of forwarding algorithm maybe included in the packet as described above.

Hereinafter, a geo-networking-related SAP (Service Access Point) isdescribed.

When the forwarding algorithm is determined by the geo-networkingprotocol layer, the packet structure of FIG. 35 may be configured by thegeo-networking protocol layer.

When the forwarding algorithm is determined by the BTP layer, theforwarding algorithm need be informed via GN-SAP by the BTP layer.GN-DATA.request for obtaining the forwarding algorithm type and theforwarding algorithm subtype may be configured as follows.

GN-DATA.request {(primitive requesting to deliver data from BTP toGeo-networking protocol layer)

Upper protocol entity, (identifies upper protocol, BTP or GN6ASL)

Packet transport type, (identifies packet transport type: GeoUnicast,SHB, TSB, etc.)

Forwarding algorithm type (Identifies the type of forwarding algorithm.The allowed values are: EGF1, EGF2, SMF1, SMF2, ECBF1, ECBF2, CSCF,ECSCF1, ECSCF2)→devised

Forwarding algorithm subtype (Identifies the sub-type of forwardingalgorithm. The allowed values are: UNSPECIFIED for EGF1, EGF2, SMF1,SMF2, ECBF1, and ECBF2, INTEGER (2 . . . 255) for CSCF, ECSCF1, andECSCF2)→devised

Destination address (Destination's Geo-networking address) Communicationprofile (identifies whether or not ITS-G5) Security profile (securityservice profile/level to be applied) ITS-AID length (length of ITS-AIDfield's value) ITS-AID (ID of application which is the destination ofdata to be delivered) Security permissions length (length of Securitypermissions field's value) Security permissions (Service SpecificPermissions associated with ITS-AID) Security context information(information for selecting Security protocol's property) Security targetID list length (length of Security target ID list field's value)Security target ID list (list of target ID used by security entity)Maximum packet lifetime (maximum time for packet preservation untilreaching destination) Repetition interval (repetition interval forpacket transmission) Maximum repetition time (total time allowed forpacket transmission with repetitions) Maximum hop limit (maximum allowedhops for packet transmission) Traffic class (packet's traffic class)Length (size of “Data” field) Data, (data requested to send by BTP toGeo-networking layer) . . . }

If the forwarding algorithm is determined by the facilities layer, theforwarding algorithm type is needed to be informed by the facilitieslayer via the NF-SAP to BTP layer before informed to Geo-networkingprotocol layer via GN-SAP. BTP-DATA.request for obtaining the forwardingalgorithm type and the forwarding algorithm subtype may be configured asfollows.

BTP-DATA.request {(primitive requesting to deliver data from facilitiesto BTP layer) BTP type, (identifies interactive (BTP-A) ornon-interactive (BTP-B)) Source port, (BTP port sending data)Destination port (BTP port to receive data) Destination port info(additional information for well-known Destination port) GN Packettransport type (identifies packet transport type: GeoUnicast, SHB, TSB,etc.)

GN Forwarding algorithm type (Identifies the type of forwardingalgorithm. The allowed values are: EGF1, EGF2, SMF1, SMF2, ECBF1, ECBF2,CSCF, ECSCF1, ECSCF2)→devised

GN Forwarding algorithm subtype (Identifies the sub-type of forwardingalgorithm. The allowed values are: UNSPECIFIED for EGF1, EGF2, SMF1,SMF2, ECBF1, and ECBF2, INTEGER (2 . . . 255) for CSCF, ECSCF1, andECSCF2)→devised

GN Destination address (Geo-networking address of destination) GNCommunication profile (identifies whether or not ITS-G5) GN Securityprofile (security service profile/level to be applied) GN Maximum packetlifetime (maximum time for packet preservation until reachingdestination) GN Repetition interval (repetition interval for packettransmission) GN Maximum repetition time (total time allowed for packettransmission with repetitions) GN Maximum hop limit (maximum allowedhops for packet transmission) GN Traffic class (packet's traffic class)Length, (size of “Data” field) Data, (data requested to send byfacilities to BTP layer) . . . }

FIG. 36 illustrates an information flow when a cellular network is notavailable according to an embodiment of the disclosure.

FIG. 37 illustrates an information flow when a cellular network isavailable according to an embodiment of the disclosure.

The disclosure may reduce the number of hops required and solve theproblems with geo-networking by using cellular technology. Since thenumber of hops required is reduced, the transmission reliability, theoverall delivery delay and network traffic are enhanced. Reducing thenumber of hops may alleviate the problems with geo-networking protocols.

FIG. 38 illustrates a V2X communication device according to anembodiment of the disclosure.

FIG. 38 is a block diagram of a hybrid V2X communication deviceaccording to an embodiment of the disclosure, and in the disclosure, thehybrid V2X communication device may be referred to as a V2Xcommunication device.

Referring to FIG. 38 , a V2X communication device 38000 may include acommunication unit 38010, a processor 38020, and a memory 38030. Asdescribed above, the V2X communication device may correspond to an onboard unit (OBU) or roadside unit (RSU) or may be included in an OBU orRSU. Or, the V2X communication device may correspond to an ITS stationor may be included in an ITS station.

The communication unit 3810 may be connected to the processor 38020 totransmit/receive a wireless signal or a wired signal. The communicationunit 38010 may up-convert data received from the processor 38020 into atransmission/reception band and transmit the signal. The communicationunit may implement the operation of the access layer. According to anembodiment, the communication unit may implement the operation of thephysical layer included in the access layer or may additionallyimplement the operation of the MAC layer. The communication unit mayalso include a plurality of sub communication units to performcommunication according to a plurality of communication protocols.

The processor 38020 may be connected with the communication unit 38010to implement the operation of the layers according to the ITS system orWAVE system. The processor 38020 may be configured to perform operationsaccording to various embodiments of the disclosure as described withreference to the drawings. Further, according to various embodiments ofthe disclosure, at least one of a module, data, program, or software forimplementing the operation of the V2X communication device 38000 may bestored in the memory 38030 and be executed by the processor 38020.

The memory 38030 is connected with the processor 38020 to store variouspieces of data/information for driving the processor 38020. The memory38030 may be included in the processor 38020 or be installed outside theprocessor 38020 and connected with the processor 38020 via a knownmeans. The memory may include a secure/non-secure storage device or beincluded in a secure/non-secure storage device. According to anembodiment, the memory may be denoted a secure/non-secure storagedevice.

The specific configuration of the V2X communication device 38000 of FIG.38 may be implemented so that the above-described various embodiments ofthe disclosure are applied independently from each other or two or morethereof are applied together.

In an embodiment of the disclosure, the communication unit may includeat least two transceivers. The communication unit may include atransceiver performing communication according to the WLAN V2Xcommunication protocol based on IEEE (Institute of Electrical andElectronics Engineers) 802.11, and a transceiver performingcommunication according to the cellular V2X communication protocol basedon LTE/E-UTRA (Evolved Universal Terrestrial Access) or 5G NR (NewRadio) of 3GPP (3rd Generation Partnership Project). The transceiverthat performs communication according to the WLAN V2X communicationprotocol, such as ITS-G5, may be referred to as a WLAN transceiver. Thetransceiver that performs communication according to the cellularcommunication protocol, such as NR, may be referred to as a cellulartransceiver.

FIG. 39 illustrates a geo-networking transmission method using hybridcommunication including direct communication and cellular communicationaccording to an embodiment of the disclosure.

The V2X communication device may receive a message from at least oneneighboring vehicle (S39010). The message may correspond to CAM, DANM,or BSM. Alternatively, the message may include a geo-networking packet.

The V2X communication device may transmit a geo-networking packet to atleast one neighboring vehicle (S39020). Geo-networking packettransmission may be performed based on at least one of a greedy-basedforwarding algorithm, a sender-managed forwarding algorithm, and acontention-based forwarding algorithm.

As illustrated in FIGS. 17 and 18 , the received message may includehybrid performance information for a neighboring vehicle. The hybridperformance information may indicate whether the neighboring vehicle iscapable of hybrid communication.

As in the embodiments of FIGS. 20 and 21 , the received message mayinclude cellular in range information. The cellular in range informationmay indicate whether the neighboring vehicle is within the coverage of acellular base station.

As in the embodiment of FIG. 34 , the transmitted geo-networking packetmay include forwarding algorithm type information. The forwardingalgorithm type information may indicate the type of forwarding algorithmthrough which a geo-networking packet is transmitted. Further, thegeo-networking packet may further include forwarding algorithm subtypeinformation.

The greedy-based forwarding algorithm may include at least one type ofan Enhanced Greedy Forwarding 1 (EFG1) algorithm or an Enhanced GreedyForwarding 2 (EFG2) algorithm. The sender managed forwarding algorithmmay include at least one type of a Sender Managed Forwarding 1 (SMF1)algorithm or a Sender Managed Forwarding 1 (SMF2) algorithm. Thecontention-based forwarding algorithm may include at least one type ofan ECBF1 (Enhanced Contention-Based Forward 1) algorithm, an ECBF2(Enhanced Contention-Based Forward 1) algorithm, a CSCF (CombinedSender-based and Contention-based Forwarding) algorithm, an ECSCF1(Enhance Combined Sender-based) and Contention-based Forwarding 1)algorithm, or an Enhance Combined Sender-based and Contention-basedForwarding 2 (ECSCF2) algorithm. The above-described forwardingalgorithm type information may indicate at least one of theabove-described forwarding algorithms described in the disclosure.

Geo-networking packet transmission may be performed by acontention-based forwarding algorithm. As in the embodiment of Equation1, the buffering time of the timer for packet forwarding may bedetermined based on the hybrid communication capability of the receiver.As in the embodiment of Equation 2, the buffering time of the timer forpacket forwarding may be determined based on the hybrid communicationcapability of the receiver and whether the receiver is within cellularcoverage. As an embodiment, the buffering time of the timer for packetforwarding may be determined based on at least one of the hybridcommunication capability of the receiver receiving a geo-networkingpacket or whether the receiver is within the cellular coverage. Areceiver capable of hybrid communication may set a shorter bufferingtime than a receiver capable of hybrid communication. Further, areceiver within cellular coverage may set a shorter buffering time thana receiver out of cellular coverage.

The above-described embodiments regard predetermined combinations of thecomponents and features of the disclosure. Each component or featureshould be considered as optional unless explicitly mentioned otherwise.Each component or feature may be practiced in such a manner as not to becombined with other components or features. Further, some componentsand/or features may be combined together to configure an embodiment ofthe disclosure. The order of the operations described in connection withthe embodiments of the disclosure may be varied. Some components orfeatures in an embodiment may be included in another embodiment or maybe replaced with corresponding components or features of the otherembodiment. It is obvious that the claims may be combined to constitutean embodiment unless explicitly stated otherwise or such combinationsmay be added in new claims by an amendment after filing.

The embodiments of the disclosure may be implemented by various means,e.g., hardware, firmware, software, or a combination thereof. Whenimplemented in hardware, an embodiment of the disclosure may beimplemented with, e.g., one or more application specific integratedcircuits (ASICs), digital signal processors (DSPs), digital signalprocessing devices (DSPDs), programmable logic devices (PLDs), fieldprogrammable gate arrays (FPGAs), processors, controllers,micro-controllers, or micro-processors.

When implemented in firmware or hardware, an embodiment of thedisclosure may be implemented as a module, procedure, or functionperforming the above-described functions or operations. The softwarecode may be stored in a memory and driven by a processor. The memory maybe positioned inside or outside the processor to exchange data with theprocessor by various known means.

It is apparent to one of ordinary skill in the art that the disclosuremay be embodied in other specific forms without departing from theessential features of the disclosure. Thus, the above description shouldbe interpreted not as limiting in all aspects but as exemplary. Thescope of the disclosure should be determined by reasonableinterpretations of the appended claims and all equivalents of thedisclosure belong to the scope of the disclosure.

Detailed Description of Exemplary Embodiments

It is appreciated by one of ordinary skill in the art that variouschanges and modifications may be made to the embodiments of thedisclosure without departing from the scope or spirit of the disclosure.Thus, all such changes or modifications are intended to belong to thescope of the disclosure as defined by the appended claims or equivalentsthereof.

The disclosure sets forth both devices and methods, and descriptionsthereof may be complementarily applicable to each other.

Various embodiments have been described in the best mode for practicingthe disclosure.

INDUSTRIAL AVAILABILITY

The disclosure is used in a series of vehicle communication fields.

It is appreciated by one of ordinary skill in the art that variouschanges and modifications may be made to the embodiments of thedisclosure without departing from the scope or spirit of the disclosure.Thus, all such changes or modifications are intended to belong to thescope of the disclosure as defined by the appended claims or equivalentsthereof

The invention claimed is:
 1. A method of geo-networking transmissionbased on hybrid communication including direct communication andcellular communication, the method comprising: receiving a message fromat least one neighboring vehicle; and transmitting a geo-networkingpacket to the at least one neighboring vehicle, wherein the transmissionof the geo-networking packet is performed based on at least oneforwarding algorithm of a greedy-based forwarding algorithm, asender-managed forwarding algorithm, or a contention-based forwardingalgorithm, wherein the received message is related to a CooperativeAwareness Message (CAM), a Decentralized Environmental NotificationMessage (DENM), or a Basic Safety Message (BSM), wherein thegreedy-based forwarding algorithm includes at least one type of anenhanced greedy forwarding 1 (EFG1) algorithm or an enhanced greedyforwarding 2 (EFG2) algorithm, wherein the sender managed forwardingalgorithm includes at least one type of a sender managed forwarding 1(SMF1) algorithm or a sender managed forwarding 1 (SMF2) algorithm, andwherein the contention-based forwarding algorithm includes an enhancedcontention-based Forward 1 (ECBF1) algorithm, an enhancedcontention-based forward 2 (ECBF2) algorithm, a combined sender-basedand contention-based forwarding (CSCF) algorithm, an enhance combinedsender-based and contention-based forwarding 1 (ECSCF1) algorithm, or anenhance combined sender-based and contention-based forwarding 2 (ECSCF2)algorithm.
 2. The method of claim 1, wherein the received messageincludes hybrid capability information for the neighboring vehicle, andwherein the hybrid capability information is related to the neighboringvehicle being capable of the hybrid communication.
 3. The method ofclaim 2, wherein the received message includes cellular in rangeinformation, and wherein the cellular in range information is related tothe neighboring vehicle being within coverage of a cellular basestation.
 4. The method of claim 1, wherein the geo-networking packetincludes forwarding algorithm type information, and wherein theforwarding algorithm type information identifies a type of forwardingalgorithm through which the geo-networking packet is transmitted.
 5. Themethod of claim 3, wherein based on the transmission of thegeo-networking packet being performed based on the contention-basedforwarding algorithm, a buffering time of a timer for packet forwardingis determined based on at least one of a hybrid communication capabilityof a receiver receiving the geo-networking packet or the receiver beingwithin the cellular coverage.
 6. A communication device performinghybrid communication including direct communication and cellularcommunication, the communication device comprising: a memory storingdata; a transceiver transmitting and receiving a wireless signalincluding a geo-networking packet; and a processor controlling thememory and the transceiver, wherein the processor: receives a messagefrom at least one neighboring vehicle; and transmits a geo-networkingpacket to the at least one neighboring vehicle, wherein the receivedmessage is related to a Cooperative Awareness Message (CAM), aDecentralized Environmental Notification Message (DENM), or a BasicSafety Message (BSM), wherein the transmission of the geo-networkingpacket is performed based on at least one forwarding algorithm of agreedy-based forwarding algorithm, a sender-managed forwardingalgorithm, or a contention-based forwarding algorithm, wherein thegreedy-based forwarding algorithm includes at least one type of anenhanced greedy forwarding 1 (EFG1) algorithm or an enhanced greedyforwarding 2 (EFG2) algorithm, wherein the sender managed forwardingalgorithm includes at least one type of a sender managed forwarding 1(SMF1) algorithm or a sender managed forwarding 1 (SMF2) algorithm, andwherein the contention-based forwarding algorithm includes an enhancedcontention-based Forward 1 (ECBF1) algorithm, an enhancedcontention-based forward 2 (ECBF2) algorithm, a combined sender-basedand contention-based forwarding (CSCF) algorithm, an enhance combinedsender-based and contention-based forwarding 1 (ECSCF1) algorithm, or anenhance combined sender-based and contention-based forwarding 2 (ECSCF2)algorithm.
 7. The communication device of claim 6, wherein the receivedmessage includes hybrid capability information for the neighboringvehicle, and wherein the hybrid capability information is related to theneighboring vehicle being capable of the hybrid communication.
 8. Thecommunication device of claim 7, wherein the received message includescellular in range information, and wherein the cellular in rangeinformation is related to the neighboring vehicle being within coverageof a cellular base station.
 9. The communication device of claim 6,wherein the geo-networking packet includes forwarding algorithm typeinformation, and wherein the forwarding algorithm type informationidentifies a type of forwarding algorithm through which thegeo-networking packet is transmitted.
 10. The communication device ofclaim 8, wherein based on the transmission of the geo-networking packetbeing performed based on the contention-based forwarding algorithm, abuffering time of a timer for packet forwarding is determined based onat least one of a hybrid communication capability of a receiverreceiving the geo-networking packet or the receiver being within thecellular coverage.